Hydrogn supply apparatus and fuel gas supply apparatus

ABSTRACT

Disclosed is a hydrogen supply apparatus which can mix an odorant with hydrogen gas even at a low temperature and can detect the leakage of the hydrogen gas. The apparatus comprises a gas storage portion which stores hydrogen gas therein, an odorant-addition portion which adds an odorant to the hydrogen gas fed from the gas storage portion, and a temperature control portion which controls the temperature of at least one of the hydrogen gas stored in the gas storage portion, the hydrogen gas fed from the gas storage portion and the odorant.

This is a 371 national phase application of PCT/JP2006/317670 filed 06Sep. 2006, claiming priority to Japanese Patent Application No.2005-259129 filed 07 Sep. 2005, and No. 2006-211730 filed 03 Aug. 2006,respectively, the contents of which are incorporated herein byreference.

FIELD OF THE INVENTION

The present invention relates to a hydrogen supply apparatus and a fuelgas supply apparatuses, each of which can be suitably used in a fuelcell system that generates electric energy by an electrochemicalreaction in particular.

BACKGROUND OF THE INVENTION

A fuel cell system for obtaining electric energy by an electrochemicalreaction between a hydrogen gas and an oxidation gas is known. Thehydrogen gas serving as a fuel for this fuel cell system is flammableand odorless. On the other hand, in handling a hydrogen gas, it ispreferable to be able to recognize the presence of the hydrogen gas withcertainty.

Therefore, a hydrogen supply apparatus that mixes a hydrogen gas with anodorant whose presence is recognizable due to its odor has been provided(see, for example, Patent Document 1). In this hydrogen supplyapparatus, since the hydrogen gas and the odorant are mixed, thehandling of the hydrogen gas is facilitated. Further, in the case wherethe leakage of the hydrogen gas has occurred, for example, the leakageof the hydrogen gas can be immediately detected due to the odor of theodorant.

[Patent document 1] JP 2002-29701 A[Patent document 2] JP 2002-216812 A[Patent document 3] JP 2004-111167 A

SUMMARY OF THE INVENTION Problems to be Solved by the Invention

In order to detect the leakage of the hydrogen gas, the odorant and thehydrogen gas have to be mixed. However, in the case where the hydrogengas has reached an extremely low temperature, the odorant has sometimesbeen solidified, and the hydrogen gas and the odorant have not beenmixed at an extremely low temperature in some cases. In a system forstoring the hydrogen gas in a high-pressure state, such as ahigh-pressure hydrogen tank in particular, the hydrogen gas has reachedan extremely low temperature due to adiabatic expansion during thehydrogen supply, and the hydrogen gas has been supplied while not beingmixed with the odorant in some cases.

The present invention has been made in view of the various problemsmentioned above, and it is an object of the present invention to providea hydrogen supply apparatus capable of mixing an odorant with a hydrogengas even at a low temperature, and detecting the hydrogen gas leakage.

Means for Solving the Problems

In order to solve the above-mentioned problems, the present inventionadopts the following means. That is, a hydrogen supply apparatusaccording to the present invention includes: gas storage portion whichstores a hydrogen gas; an odorant addition portion which adds an odorantto the hydrogen gas; and a temperature adjustment portion which adjustsa temperature of at least one of the hydrogen gas, the odorant, and thehydrogen gas to which the odorant has been added.

In the hydrogen supply apparatus, upon supply of the hydrogen gas storedin the gas storage portion to the outside thereof, the pressure of thehydrogen gas is reduced, and the hydrogen gas undergoes adiabaticexpansion. Thus, the temperature of the hydrogen gas is reduced. Whenthe temperature of the hydrogen gas is reduced to a level equal to orlower than a predetermined temperature, the odorant to be mixed with thehydrogen gas is solidified or liquefied, and may have difficulty inmixing with the hydrogen gas.

The hydrogen supply apparatus according to the present inventionincreases the temperature of at least one of the hydrogen gas and theodorant by the temperature adjustment portion to suppress a temperaturereduction in hydrogen gas, thus making it possible to maintain theodorant in a state in which (or at a temperature at which) the odorantcan be mixed with the hydrogen gas. The hydrogen gas whose temperatureis increased may be a hydrogen gas stored in the gas storage portion, ormay be a hydrogen gas supplied to the outside from the gas storageportion. Further, the hydrogen gas supplied to the outside includes ahydrogen gas to which the odorant has been added. It should be notedthat the hydrogen gas supply apparatus according to the presentinvention can add the odorant to the hydrogen gas by including odorantaddition portion. The hydrogen gas to which the odorant is to be addedmay be a hydrogen gas stored in the gas storage portion, or may be ahydrogen gas discharged from the gas storage portion. Further, thehydrogen gas, to which the odorant has been added by the odorantaddition portion, is supplied to the supply destination for the hydrogengas, i.e., a hydrogen gas utilization apparatus such as a fuel cell or ahydrogen engine.

Further, a hydrogen supply apparatus according to the present inventionmay be characterized by further including stored gas temperaturedetection portion which detects the temperature of the hydrogen gasstored in the gas storage portion, and characterized in that thetemperature adjustment portion has a gas temperature reductionsuppression portion which suppresses a temperature reduction in hydrogengas stored in the gas storage portion, when the temperature of thehydrogen gas detected by the stored gas temperature detection portion isequal to or lower than a predetermined temperature.

When the temperature of the hydrogen gas is equal to or lower than thepredetermined temperature, a temperature reduction in hydrogen gas issuppressed by the gas temperature reduction suppression portion, thusmaking it possible to maintain the odorant in a state in which (or at atemperature at which) the odorant can be mixed with the hydrogen gas. Itshould be noted that the hydrogen gas may be one mixed with the odorant.With the use of the hydrogen gas mixed with the odorant, the hydrogengas mixed with the odorant can be supplied, and the detection accuracyof the hydrogen gas leakage can be improved. The predeterminedtemperature refers to a temperature below which the odorant is changedinto, for example, a solid form incapable of mixing with the hydrogengas, and is appropriately set in accordance with the properties of theodorant.

Further, a hydrogen supply apparatus according to the present inventionmay be characterized by further including hydrogen gas temperaturedetection portion which detects the temperature of the hydrogen gassupplied from the gas storage portion, and characterized in that thetemperature adjustment portion has a heating portion which increases thetemperature of the hydrogen gas supplied from the gas storage portion,when the temperature of the hydrogen gas detected by the hydrogen gastemperature detection portion is equal to or lower than a predeterminedtemperature.

The above-mentioned stored gas temperature detection portion detects thetemperature of the hydrogen gas stored in the gas storage portion; onthe other hand, the hydrogen gas temperature detection portion detectsthe temperature of the hydrogen gas, supplied to the outside of the gasstorage portion, at the outside of the gas storage portion. That is, thehydrogen gas temperature detection portion is capable of detecting thetemperature of the hydrogen gas to be supplied to the outside of the gasstorage portion, which has been reduced due to adiabatic expansion.Based on the temperature of the hydrogen gas detected, the temperatureadjustment portion increases the temperature of the hydrogen gassupplied from the gas storage portion, thereby making it possible tosuppress the liquefaction or solidification of the odorant, resultingfrom the cooling thereof by the hydrogen whose temperature has beenreduced. It should be noted that the heating means portion may be anyportion as long as it is capable of increasing the temperature of thehydrogen gas, and an example of which may be a heater.

Further, the hydrogen supply apparatus according to the presentinvention may be characterized by further including an odoranttemperature detection portion which detects the temperature of theodorant to be added by the odorant addition portion, in which thetemperature adjustment portion has a heating portion which increases thetemperature of the odorant to be added by the odorant addition portion,when the temperature of the odorant detected by the odorant temperaturedetection portion is equal to or lower than a predetermined temperature.

In order to increase the temperature of the odorant, it is preferable tocalculate the vapor pressure of the odorant from the temperature of theodorant detected, and to apply heat to the odorant so that it reaches anecessary vapor pressure. The necessary vapor pressure refers to apressure at which the odorant added to the hydrogen gas does not liquefyor solidify. The supply of heat to the odorant may be carried out byproviding an odorant storage portion which stores an odorant, forexample, and by raising the temperature of the odorant storage portionusing a heating portion such as a heater. By adjusting the vaporpressure of the odorant in this manner, the liquefaction orsolidification of the odorant can be suppressed. It should be noted thatthe heating portion may be any portion as long as it can increase thetemperature of the odorant, and an example of which may be a heater.

Further, the hydrogen supply apparatus according to the presentinvention may be characterized by further including: a hydrogen gastemperature detection portion which detects the temperature of thehydrogen gas supplied from the gas storage portion; and an odoranttemperature detection portion which detects the temperature of theodorant added by the odorant addition portion, in which the temperatureadjustment portion has a heating portion which increases the temperatureof the odorant when at least one of the temperature of the hydrogen gasdetected by the hydrogen gas temperature detection portion and thetemperature of the odorant detected by the odorant temperature detectionportion meets a predetermined condition.

In the present invention, the temperature of the odorant is adjusted notonly based on the temperature of the odorant detected by the odorantdetection portion, but also based on the temperature of the odorantdetected by the hydrogen gas detection portion. The predeterminedcondition portion determines that the temperature of the hydrogen gasdetected by the hydrogen gas temperature detection portion is equal toor lower than a predetermined temperature, or the temperature of theodorant detected by the odorant temperature detection portion is equalto or lower than a predetermined temperature. It should be noted thattemperatures to be employed may be prioritized, and the temperature ofthe odorant may be increased based on a high-priority temperature. Theheating portion may be any portion as long as it can increase thetemperature(s) of the hydrogen gas and/or the odorant, and an example ofwhich may be a heater.

Further, a hydrogen supply apparatus according to the present inventionmay be characterized by further including a hydrogen gas temperaturedetection portion which detects the temperature of the hydrogen gassupplied from the gas storage portion, and characterized in that thetemperature adjustment portion has a heating portion which increases thetemperature of the hydrogen gas which is supplied from the gas storageportion and to which the odorant has been added by the odorant additionportion, when the temperature of the hydrogen gas detected by thehydrogen gas temperature detection portion is equal to or lower than apredetermined temperature.

According to the present invention, the temperature of the hydrogen gas,to which the odorant has been added by the odorant addition portion, isadjusted, thereby suppressing the liquefaction or solidification of theodorant contained in the hydrogen gas. As described above, upon supplyof the hydrogen gas stored in the gas storage portion to the outsidethereof, the temperature may be reduced due to adiabatic expansion.However, the causes of the temperature reduction in hydrogen gas are notlimited to this, and it may also be possible that the temperature of thehydrogen gas is reduced, for example, by placing the hydrogen gas supplyapparatus in a below-freezing environment. Even if the hydrogen gas orodorant is heated, the temperature reduction in hydrogen gas due to sucha cause may occur because of the subsequent gradual loss of heat fromthe hydrogen gas, for example. According to the present invention, thetemperature of the hydrogen gas after the addition of the odorant can beincreased, and therefore, the liquefaction or the like of the odorantcan be prevented even if the hydrogen gas supply apparatus is placed ina below-freezing environment.

Further, a hydrogen supply apparatus according to the present inventionmay be characterized by further including a hydrogen gas supply amountadjustment portion which adjusts a supply amount of the hydrogen gassupplied from the gas storage portion, and characterized in that thetemperature adjustment portion decreases the supply amount of thehydrogen gas, supplied from the gas storage portion, by the hydrogen gassupply amount adjustment portion, to thereby suppress a temperaturereduction in hydrogen gas.

Upon supply of the hydrogen gas from the gas storage portion to theoutside thereof, the hydrogen gas inside the gas storage portion isdecreased, and the temperature of the hydrogen gas is reduced due toadiabatic expansion. In particular, if the hydrogen gas is stored in ahigh-pressure state in a high-pressure hydrogen tank, for example, thepressure is sharply reduced, which results in a significant temperaturereduction. However, upon decrease in the supply amount of the hydrogengas, the temperature reduction is decreased.

Accordingly, when the temperature of the hydrogen gas is equal to orlower than the predetermined temperature, the supply amount of thehydrogen gas is preferably decreased by the hydrogen gas supply amountadjustment portion, and the temperature reduction can be suppressed tofacilitate the mixing of the odorant with the hydrogen gas by decreasingthe supply amount of the hydrogen gas.

Further, a hydrogen supply apparatus according to the present inventionmay be characterized in that the predetermined temperature is equal toor higher than a melting point of the odorant. That is, when thetemperature of the hydrogen gas detected by the stored gas temperaturedetection portion or the hydrogen gas temperature detection portion isequal to or lower than the predetermined temperature that is equal to orhigher than the melting point of the odorant, the temperature adjustmentportion increases the temperature of at least one of the hydrogen storedin the gas storage portion, the hydrogen gas supplied from the gasstorage portion, and the odorant.

The melting point of the odorant is a temperature at which the odorantchanges from a solid form to a liquid form. When the temperature of theodorant is reduced to be lower than the melting point thereof, theodorant is turned into a solid form, which has difficulty in mixing withthe hydrogen gas. At such a temperature, the hydrogen gas and theodorant may not be mixed, and the detection accuracy of the hydrogen gasleakage may be degraded.

Accordingly, the predetermined temperature is set equal to or higherthan the melting point of the odorant so as to suppress a temperaturereduction in hydrogen gas when the temperature of the hydrogen gas isequal to or lower than the predetermined temperature, therebysuppressing the solidification of the odorant, and allowing the odorantto be present in a liquid form or in a gaseous form. Generally, it isdifficult to mix the odorant in a solid form with the hydrogen gas, andtherefore, the odorant is provided in a liquid form or in a gaseousform, thus facilitating the mixing of the odorant with the hydrogen gas.

It should be noted that the predetermined temperature is set equal to orhigher than the melting point of the odorant because it is suitable forthe odorant, which can be mixed with the hydrogen gas or is easily mixedtherewith in a liquid state, and this temperature is appropriatelychanged in accordance with the properties of the odorant.

Further, a hydrogen supply apparatus according to the present inventionmay be characterized in that the predetermined temperature is equal toor higher than a boiling point of the odorant. That is, when thetemperature of the hydrogen gas, detected by the gas temperaturedetection portion, is equal to or lower than the predeterminedtemperature that is equal to or higher than the boiling point of theodorant, the gas temperature reduction suppression portion increases thetemperature of at least one of the hydrogen stored in the gas storageportion, the hydrogen gas supplied from the gas storage portion, and theodorant.

The boiling point of the odorant is a temperature at which the odorantchanges from a liquid form to a gaseous form. When the temperature ofthe odorant is reduced to be lower than the boiling point thereof, theodorant is changed into a liquid form, which may have difficulty inmixing with the hydrogen gas depending on the properties of the odorant.The odorant, which will not be mixed with the hydrogen gas or havedifficulty in mixing therewith in a liquid state, may degrade thedetection accuracy of the hydrogen gas leakage.

Accordingly, by suppressing a temperature reduction in hydrogen gas whenthe temperature of the hydrogen gas is at the predetermined temperaturethat is equal to or higher than the boiling point of the odorant, theodorant is kept in a gaseous state, thus making it possible tofacilitate the mixing of the odorant with the hydrogen gas.

It should be noted that the predetermined temperature is set equal to orhigher than the boiling point of the odorant because it is suitable forthe odorant, which can be mixed with the hydrogen gas or is easily mixedtherewith in a gaseous state, and this temperature is appropriatelychanged in accordance with the properties of the odorant.

Further, a hydrogen supply apparatus according to the present inventionmay be characterized by including: a gas storage portion which stores ahydrogen gas mixed with an odorant; a gas supply portion which suppliesthe hydrogen gas from the gas storage portion; and a gas temperaturedetection portion which detects the temperature of the hydrogen gasstored in the gas storage portion; and a gas temperature reductionsuppression portion which suppresses a temperature reduction in hydrogengas stored in the gas storage portion, when the temperature of thehydrogen gas detected by the gas temperature detection portion is equalto or lower than a predetermined temperature.

By suppressing a temperature reduction in hydrogen gas using the gastemperature reduction suppression portion when the temperature of thehydrogen gas mixed with the odorant is equal to or lower than thepredetermined temperature, the odorant can be maintained in a state inwhich (or at a temperature at which) it can be mixed with the hydrogengas. Accordingly, the hydrogen gas mixed with the odorant can besupplied, thus enabling an improvement in the detection accuracy of thehydrogen gas leakage. The predetermined temperature is a temperaturebelow which the odorant is changed into a solid state, for example,which cannot be mixed with the hydrogen gas, and is appropriately set inaccordance with the properties of the odorant.

Further, a hydrogen supply apparatus according to the present inventionmay be characterized by further including a hydrogen gas temperaturedetection portion which detects the temperature of the hydrogen gassupplied from the gas storage portion, and characterized in that thetemperature adjustment portion has a heating portion which increases thetemperature of the hydrogen gas which is supplied from the gas storageportion and to which the odorant has been added by the odorant additionportion, when the temperature of the hydrogen gas detected by thehydrogen gas temperature detection portion is equal to or lower than apredetermined temperature. Thus, it is possible to increase thetemperature of the hydrogen gas, which has been mixed with the odorant,and which is to be supplied to the outside from the gas storage portion.

Besides, the hydrogen supply apparatus according to the presentinvention may be characterized in that the gas temperature reductionsuppression portion suppresses a temperature reduction in hydrogen gasby decreasing the supply amount of the hydrogen gas.

The hydrogen supply apparatus according to the present invention issatisfactory as long as it can suppress a temperature reduction inhydrogen gas when the temperature of the hydrogen gas is equal to orlower than a predetermined temperature at which the hydrogen gas hasdifficulty in mixing with the odorant; for example, in addition to theabove-mentioned configurations, the apparatus may be provided with alimiter for stopping the supply of the hydrogen gas when the temperaturethereof is equal to or lower than the predetermined temperature, so asto prevent a decrease in the hydrogen gas inside a hydrogen storagedevice, and to suppress a temperature reduction in hydrogen gas, or theapparatus may be provided with a plurality of gas storage portions so asto use the hydrogen gas inside the gas storage portion in which thetemperature of the hydrogen gas is higher than the predeterminedtemperature, without the use of the gas storage portion in which thetemperature of the hydrogen gas is lower than the predeterminedtemperature, thereby maintaining the temperature of the hydrogen gas tobe supplied above the predetermined temperature.

Actually, each of the hydrogen supply apparatuses described above is anapparatus for supplying a hydrogen gas as a fuel gas. It should be notedthat problems that the odorant is not solidified at a low temperatureand the hydrogen gas is not mixed with the odorant at an extremely lowtemperature are not limited to the hydrogen gas, but those problems arepossible in general fuel gas. Accordingly, an object of the presentinvention is to provide a fuel gas supply apparatus capable of mixing anodorant with a fuel gas even at a low temperature, and detecting thefuel gas leakage.

In order to solve the above-mentioned problems, the present inventionadopts the following portion. That is, a fuel gas supply apparatusaccording to the present invention is characterized by including: a gasstorage portion which stores a fuel gas; an odorant addition portionwhich adds an odorant to the fuel gas; and a temperature adjustmentportion which adjusts the temperature of at least one of the hydrogengas, the odorant, and the hydrogen gas to which the odorant has beenadded.

The fuel gas supply apparatus according to the present invention hasfunctions equivalent to those of each hydrogen supply apparatus alreadydescribed above. This is because “fuel gas” is a generic name for anatural gas, a liquefied petroleum gas and the like, and a hydrogen gasis also included in a fuel gas. Accordingly, the configuration of theabove-mentioned fuel gas supply apparatus can be described by replacingthe hydrogen gas in each hydrogen supply apparatus already describedabove with a fuel gas. Therefore, the description thereof will beomitted.

It should be noted that examples of the fuel gas include a natural gas,and a liquefied petroleum gas (LPG) composed of propane and butane andutilized as a mixture thereof. It should be noted that the natural gasincludes a compressed natural gas (hereinafter, referred to as “CNG”).Further, if hydrogen is reformed by a reformer, a resultant reformed gasis also included in the fuel gas. Further, the fuel gas supply apparatusfor supplying those fuel gases is applicable to a fuel cell serving as afuel gas consumption device that consumes a fuel gas, a hydrogen engine,a CNG engine, an LPG engine, and a reformer for reforming a fuel gas,for example. It should be noted that a reformer for reforming a fuel gasrefers to a reformer for reforming, for example, a fuel gas to hydrogen.

According to the hydrogen supply apparatus of the present invention, atemperature reduction in a hydrogen gas can be suppressed even at a lowtemperature, an odorant and a hydrogen gas can be mixed, and thehydrogen gas leakage can be detected.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 A block diagram of a fuel cell system 10 according to Embodiment1.

FIG. 2 A flow chart illustrating the temperature control of a hydrogengas in the fuel cell system 10 according to Embodiment 1.

FIG. 3 A flow chart illustrating the temperature control of a hydrogengas in the fuel cell system 10 according to Embodiment 2.

FIG. 4 A block diagram of a water fuel cell system 11 according toEmbodiment 3.

FIG. 5 A flow chart illustrating the temperature control of a hydrogengas according to Embodiment 3.

FIG. 6 A map of a necessary heating amount.

FIG. 7 A block diagram of a fuel cell system 12 according to Embodiment4.

FIG. 8 A flow chart illustrating the vapor pressure control of anodorant according to Embodiment 4.

FIG. 9 A block diagram of a fuel cell system 13 according to Embodiment5.

FIG. 10 A block diagram of a fuel cell system 14 according to Embodiment6.

FIG. 11 A flow chart illustrating the temperature control of a hydrogengas according to Embodiment 6.

DETAILED DESCRIPTION

Embodiments of hydrogen supply apparatuses according to the presentinvention will be described in detail with reference to the drawings.

Embodiment 1

FIG. 1 is a system block diagram of a fuel cell system 10 including ahydrogen supply apparatus according to Embodiment 1. This fuel cellsystem includes: a fuel cell 1; a high-pressure hydrogen tank 2 whichstores a hydrogen gas serving as a fuel gas, and which functions as ahydrogen supply apparatus for supplying the hydrogen gas to the fuelcell 1; an air supply apparatus 3 for supplying air to the fuel cell 1;and an electronic control unit (ECU) 4 for controlling the variousapparatuses.

The high-pressure hydrogen tank 2 includes: a tank 21 serving as gasstorage portion in which the hydrogen gas mixed with an odorant isstored; a main stop valve 22 through which the hydrogen gas is suppliedto the fuel cell 1; a heater 23 serving as a heating portion forincreasing the temperature of the hydrogen gas inside the tank 21; and athermometer 24 serving as a gas temperature detection portion whichdetects the temperature of the hydrogen gas inside the tank 21.

The fuel cell 1 causes an electrochemical reaction between the hydrogengas and an oxidation gas via an electrolyte to obtain electric energy.The fuel cell 1 according to Embodiment 1 is a solid polymer electrolytefuel cell frequently used in an electric automobile that runs using afuel cell as a power supply.

The hydrogen gas stored in the high-pressure hydrogen tank 2 containsmethyl acrylate as an odorant. The odorant gives the hydrogen gas anodor by mixing the odorant into an odorless hydrogen gas, and serves todetect the hydrogen gas leakage. The methyl acrylate has a boiling pointof about 80° C. and a melting point of about −75° C.

The main stop valve 22 serves as a supply port through which thehydrogen gas is supplied from the tank 21 to the fuel cell 1, and asupply flow rate therethrough is controlled by the ECU 4. Further, themain stop valve 22 is a solenoid valve, which is heated by passing anelectric current therethrough, and which can indirectly heat thehydrogen gas to be supplied to the fuel cell 1. That is, the main stopvalve 22 has a function of a heating portion like the heater 23.

The heater 23 is disposed at a lower part of the tank 21, and candirectly heat the hydrogen gas inside the tank 21 with the control ofthe ECU 4. The position at which the heater 23 is placed may be anyposition as long as the hydrogen gas inside the tank 21 can be heated,and is not limited to the lower part of the tank 21; however, when theodorant is in a solid form or in a liquid form, the hydrogen gas isaccumulated at the lower part of the tank 21, and therefore, thehydrogen gas can be efficiently heated by placing the heater 23 at thelower part of the tank 21.

The thermometer 24 serves to detect the temperature of the hydrogen gasinside the tank 21, and is configured so that the temperature of thehydrogen gas detected is inputted to the ECU 4. The ECU 4 controls themain stop valve 22 or the heater 23 based on the temperature of thehydrogen gas detected by the thermometer 24, thereby maintaining thehydrogen gas inside the tank 21 at an appropriate temperature.

Hereinafter, the temperature control of the hydrogen gas in the fuelcell system 10 configured as described above will be described indetail. Each of the various controls described below is executed by theECU 4, and is a routine repeated at regular intervals.

Embodiment 1 provides temperature control prior to the start of supplyof the hydrogen gas, and is an embodiment in which when the temperatureof the hydrogen gas inside the high-pressure hydrogen tank 2 is equal toor lower than a predetermined temperature, the temperature of thehydrogen gas is increased by the heater 23 or the main stop valve 22 tocreate a state where the mixing of the odorant with the hydrogen gas isfacilitated, thus supplying the hydrogen gas mixed with the odorant tothe fuel cell. FIG. 2 is a flow chart illustrating the temperaturecontrol of the hydrogen gas according to Embodiment 1.

First, at the start of the supply of the hydrogen gas from thehigh-pressure hydrogen tank 2 to the fuel cell 1, the temperature of thehydrogen gas inside the tank 21 is detected by the thermometer 24 (Step101). The detected temperature is inputted to the ECU 4, and the ECU 4determines whether the detected temperature is equal to or lower than apredetermined temperature T1 (Step 102).

In Embodiment 1, methyl acrylate is used as the odorant, and thepredetermined temperature T1 is set to −70° C., which is 5° C. higherthan −75° C., i.e., the melting point of methyl acrylate. That is, at atemperature higher than the predetermined temperature T1, the methylacrylate is present as a liquid, and is in a state in which the methylacrylate is easily mixed with the hydrogen gas.

When the temperature of the hydrogen gas detected is equal to or lowerthan the predetermined temperature T1, the ECU 4 carries out a heatingprocess so as to prevent the odorant from being solidified (Step 103).In the heating process, the hydrogen gas may be directly heated bypassing an electric current through the heater 24, or the hydrogen gasto be supplied may be indirectly heated by passing an electric currentthrough the main stop valve 22. After having carried out the heatingprocess for a certain period of time by any one of methods, thetemperature of the hydrogen gas inside the tank 21 is detected again bythe thermometer 24 (Step 101).

It is determined again whether the temperature of the hydrogen gasdetected is equal to or lower than T1 (Step 102), and the heatingprocess is repeated until it is determined that the temperature of thehydrogen gas inside the tank 21 is higher than the predeterminedtemperature T1. If the temperature of the hydrogen gas detected by thethermometer 24 is determined to be higher than the predeterminedtemperature T1 as a result of the determination of Step 102, it isdetermined that the methyl acrylate serving as the odorant is in aliquid form and is mixed with the hydrogen gas, thus starting the supplyof the hydrogen gas (Step 104).

It should be noted that if the supply of the hydrogen gas is continued,the temperature thereof is reduced due to the adiabatic expansion of thehydrogen gas, and therefore, the present control is repeated at certainperiods of time even after the supply of the hydrogen gas has beenstarted. As described above, according to Embodiment 1, the hydrogen gascan be supplied at a temperature at which the odorant is easily mixedwith the hydrogen gas, thus facilitating the mixing of the hydrogen gaswith the odorant, and enabling an improvement in the detection accuracyof the hydrogen gas leakage.

Further, in Embodiment 1, the temperature control of the hydrogen gas isperformed before the start of supply of the hydrogen gas, but thetemperature control does not necessarily have to be performed before thestart of supply of the hydrogen gas, and may be performed during thesupply of the hydrogen gas. It should be noted that when the temperaturecontrol is performed during the supply of the hydrogen gas, a hydrogensupply stopping portion which stops the supply of the hydrogen gas mayfurther be provided, if the temperature of the hydrogen gas is equal toor lower than the predetermined temperature T1. By providing thehydrogen supply stopping portion, the supply of the hydrogen gas equalto or lower than the predetermined temperature is stopped, thus makingit possible to prevent the hydrogen gas, which is not mixed with theodorant at a low temperature, from being supplied to the fuel cell 1.

Embodiment 2

In Embodiment 2, when the temperature of the hydrogen gas inside thehigh-pressure hydrogen tank 2 is equal to or lower than thepredetermined temperature, the flow rate of the hydrogen gas to besupplied to the fuel cell 1 is reduced, thereby preventing a decrease inthe hydrogen gas inside the tank 21. By preventing the decrease in thehydrogen gas inside the tank 21, the temperature reduction in hydrogengas due to adiabatic expansion is suppressed. The hydrogen gastemperature control according to Embodiment 2 is the temperature controlcarried out during the supply of the hydrogen gas. It should be notedthat the configuration of the fuel cell system is substantially the sameas in Embodiment 1; therefore, the same components are identified by thesame reference numerals, and the description thereof will be omitted.

In the fuel cell system 10 according to Embodiment 2, the ECU 4, servingas gas temperature control portion, has a function of adjusting thesupply flow rate of the hydrogen gas to be supplied from thehigh-pressure hydrogen tank 2 to the fuel cell 1. If the temperatureindicated by the thermometer 24 serving as gas temperature detectionportion is equal to or lower than a predetermined temperature, the ECU 4reduces the supply flow rate of the hydrogen gas to suppress theadiabatic expansion of the hydrogen gas inside the tank 21, and tosuppress the temperature reduction in hydrogen gas inside the tank 21.By suppressing the temperature reduction in hydrogen gas in this manner,the odorant contained in the hydrogen gas can be maintained at atemperature higher than a constant temperature at which the odorant iseasily mixed with the hydrogen gas, and the hydrogen gas mixed with theodorant can be furnished to the fuel cell 1.

FIG. 3 is a flow chart illustrating the temperature control of thehydrogen gas according to Embodiment 2. First, the hydrogen gas issupplied from the high-pressure hydrogen tank 2 to the fuel cell 1 at asupply flow rate Q1 (Step 201). After a certain period of time haspassed since the supply of the hydrogen gas, the temperature of thehydrogen gas inside the tank 21 is detected by the thermometer 24 (Step202). The detected temperature is inputted to the ECU 4, and the ECU 4determines whether the temperature of the hydrogen gas detected is equalto or lower than a predetermined temperature T2 (Step 203).

Also in Embodiment 2, similarly to Embodiment 1, methyl acrylate is usedas the odorant. However, the predetermined temperature T2 is set to −65°C., which is 10° C. higher than −75° C., i.e., the melting point ofmethyl acrylate. The reason the predetermined temperature T2 is sethigher than the predetermined temperature in Embodiment 1 is that inEmbodiment 1, the temperature reduction to the predetermined temperatureT1 or lower is impossible since the hydrogen gas is heated by theheating portion, but in Embodiment 2, the slight temperature reductionto the predetermined temperature T2 or lower is possible since thetemperature reduction is suppressed without performing any heatingprocess. Accordingly, the predetermined temperature T2 in Embodiment 2is set 5° C. higher than the predetermined temperature T1 in Embodiment1.

If the temperature of the hydrogen gas detected is equal to or lowerthan the predetermined temperature T2, the ECU 4 changes the supply flowrate of the hydrogen gas from Q1 to Q2 (where Q2<Q1) in order tosuppress the temperature reduction in hydrogen gas (Step 204). Byreducing the supply flow rate of the hydrogen gas, the adiabaticexpansion of the hydrogen gas inside the tank 21 is suppressed, and thetemperature reduction in hydrogen gas is suppressed.

After having supplied the hydrogen gas to the fuel cell 1 at the supplyflow rate Q2 for a certain period of time, the temperature of thehydrogen gas is detected again (Step 202). The ECU 4 determines whetherthe temperature of the hydrogen gas detected is equal to or lower thanthe predetermined temperature T2 (Step 203), and the hydrogen gas issupplied at the supply flow rate Q2 until the temperature of thehydrogen gas is determined to be higher than the predeterminedtemperature T2. If the temperature of the hydrogen gas detected by thethermometer 24 is determined to be higher than the predeterminedtemperature T2 as a result of the determination of Step 203, the supplyflow rate of the hydrogen gas is changed from Q2 to Q1, and the hydrogengas is supplied at the supply flow rate Q1 (Step 205).

By detecting the temperature of the hydrogen gas during the supply ofthe hydrogen gas and reducing the supply flow rate of the hydrogen gaswhen the temperature of the hydrogen gas is reduced nearly to themelting point in this manner, the hydrogen gas can be supplied at atemperature at which the odorant is easily mixed with the hydrogen gas,thus making it possible to facilitate the mixing of the hydrogen gaswith the odorant, and to improve the detection accuracy of the hydrogengas leakage.

Alternatively, in another embodiment, a fuel cell system including theplurality of high-pressure hydrogen tanks 2 may be configured so that,instead of reducing the supply flow rate of the hydrogen gas when thetemperature of the hydrogen gas is equal to or lower than thepredetermined temperature T2, the high-pressure hydrogen tank, in whichthe temperature of the hydrogen gas is higher than the predeterminedtemperature T2, is selected to supply the hydrogen gas from thehigh-pressure hydrogen tank to the fuel cell.

Embodiment 3

Next, a fuel cell system 11 including a hydrogen supply apparatusaccording to Embodiment 3 will be described. In the fuel cell system 10according to Embodiment 1, the hydrogen gas inside the tank 21 isdirectly heated by the control of the ECU 4. On the other hand, in thefuel cell system 11 according to Embodiment 3 heats the hydrogen gas,which has undergone adiabatic expansion and which is to be supplied fromthe high-pressure hydrogen tank 2. Upon supply of the hydrogen gasinside the high-pressure hydrogen tank 2 to the outside thereof, thehydrogen gas to be supplied may undergo adiabatic expansion due topressure drop, and the temperature thereof may be reduced. Further, in abelow-freezing environment, the temperature of the hydrogen gas isreduced. Upon reduction of the temperature of the hydrogen gas, therearises a problem that the odorant to be mixed therewith is liquefied orsolidified. The fuel cell system 11 according to Embodiment 3 solvessuch a problem.

FIG. 4 is a system block diagram of the fuel cell system 11 includingthe hydrogen supply apparatus according to Embodiment 3. The fuel cellsystem 11 includes: the fuel cell 1; the high-pressure hydrogen tank 2;the air supply apparatus 3; the ECU 4; an odorant tank 5; a buffer tank6; a heater 23 a; a thermometer 24 a; a hydrogen gas supply passage 30;an air supply passage 31; an anode off-gas passage 32; a circulating gaspassage 33; and a hydrogen gas supply branch passage 34. It should benoted that the components already described above are identified by thesame reference numerals, and thus the detailed description thereof willbe omitted.

The hydrogen gas supply passage 30 is connected, at its one end, to thehigh-pressure hydrogen tank 2, and is connected, at its other end, tothe anode side of the fuel cell 1 to guide the hydrogen gas to the fuelcell 1. The hydrogen gas supply passage 30 is provided with a hydrogenflowmeter 27, the thermometer 24 a, and the heater 23 a in this orderfrom the upstream side of the flow of the hydrogen gas.

The hydrogen flowmeter 27 detects the flow rate of the hydrogen gassupplied from the high-pressure hydrogen tank 2. The hydrogen flowmeter27 is electrically connected to the ECU 4, and the detected hydrogenflow rate is inputted to the ECU 4. Further, the thermometer 24 adetects the temperature of the hydrogen gas supplied from thehigh-pressure hydrogen tank 2. The thermometer 24 a is electricallyconnected to the ECU 4, and the detected temperature is inputted to theECU 4.

The heater 23 a is provided to the hydrogen supply passage 30, and heatsthe hydrogen gas, passing through the hydrogen supply passage 30, by thecontrol of the ECU 4. The heater 23 a can be placed, for example, at alower part of the hydrogen supply passage 30, but is preferably placedso as to cover the hydrogen gas supply passage 30. This is because thehydrogen gas passing through the hydrogen gas supply passage 30 can beheated efficiently in such a configuration.

The hydrogen gas supply branch passage 34 branches off from the hydrogengas supply passage 30 at the downstream side of the heater 23 a, andmerges with the hydrogen gas supply passage 30 again. Further, thehydrogen gas supply branch passage 34 is provided with a pump 25, theodorant tank 5, the buffer tank 6, and an injector 26 in this order fromthe upstream side of the flow of the hydrogen gas.

The pump 25 adjusts the flow rate of the hydrogen gas to which theodorant is to be added. The odorant tank 5 stores the odorant to beadded to the hydrogen gas supplied from the high-pressure hydrogen tank2. The buffer tank 6 temporarily retains the hydrogen gas supplied fromthe high-pressure hydrogen tank 2, adds the odorant, stored in theodorant tank 5, to the hydrogen gas, and carries out agitation. Further,the injector 26 is supplied with the hydrogen gas, to which the odorantis added, from the high-pressure hydrogen tank 2, and mixes thishydrogen gas with the hydrogen gas guided through the hydrogen gassupply passage 30 functioning as a main passage.

The air supply passage 31 is connected, at its one end, to the airsupply apparatus 3, and is connected, at its other end, to the cathodeside of the fuel cell 1 to guide air to the fuel cell 1. The anodeoff-gas passage 32 guides an anode off-gas, discharged from the anodeside of the fuel cell 1, to the outside of the fuel cell system 11. Thecirculating gas passage 33 branches off from the anode of f-gas passage,and merges with the hydrogen gas supply passage to guide the hydrogengas, contained in the anode off-gas, to the fuel cell 1 again.

Hereinafter, the temperature control of the hydrogen gas in the fuelcell system 11 configured as described above will be described indetail. Each of the various controls described below is executed by theabove-mentioned ECU 4, and is a routine repeated at regular intervals.

FIG. 5 is a flow chart illustrating the temperature control of thehydrogen gas according to Embodiment 3. First, the ECU 4 obtains theflow rate of the hydrogen gas supplied from the high-pressure hydrogentank 2 to the fuel cell 1 (Step 301). The flow rate of the hydrogen gascan be obtained by the hydrogen flowmeter 27.

Next, the ECU 4 determines, from a map, a heater heating amountassociated with the obtained hydrogen flow rate (Step 302). In thisregard, a map of a necessary heating amount is shown in FIG. 6. As shownin FIG. 6, the horizontal axis represents the hydrogen flow rate(NL/min), the vertical axis represents the heater heating amount (W),and the straight line P1 represents a variation in the heater heatingamount. Such a map of the necessary heating amount may be stored inadvance in a memory or the like of the ECU 4, for example.

Then, the ECU 4 obtains the temperature of the hydrogen gas suppliedfrom the high-pressure hydrogen tank 2 (Step 303). The temperature ofthe hydrogen gas can be obtained by the thermometer 24 a. Subsequently,the ECU 4 determines whether the temperature of the hydrogen gasobtained is sufficiently high (Step 304). It should be noted that thesufficiently high temperature of the hydrogen gas portion a temperatureat which the odorant to be added does not liquefy or solidify, and maybe appropriately set depending on the odorant to be added. If thetemperature of the hydrogen gas obtained is determined to besufficiently high, the ECU 4 ends the temperature control process forthe hydrogen gas according to Embodiment 3.

On the other hand, if the temperature of the hydrogen gas obtained isnot determined to be sufficiently high, the ECU 4 determines whether thetemperature of the hydrogen gas obtained is equal to or lower than apredetermined temperature T3 (Step 305). If the temperature of thehydrogen gas is determined to be equal to or lower than thepredetermined temperature T3, the ECU 4 increases the heating amount(Step 306), and ends the temperature control process for the hydrogengas according to Embodiment 3. It should be noted that the predeterminedtemperature T3 may be the melting point or the boiling point of theodorant.

As described above, in the temperature control of the hydrogen gasaccording to Embodiment 3, the ECU 4 determines the heater heatingamount from the map, and corrects the determined heater heating amountby the obtained temperature. Thus, the ECU 4 can obtain a more accurateheater heating amount. As a result, in the case where the temperature ofthe hydrogen gas to be supplied is reduced due to adiabatic expansion orthe like, the odorant can be prevented from being liquefied orsolidified.

Embodiment 4

Next, a fuel cell system 12 including a hydrogen supply apparatusaccording to Embodiment 4 will be described. FIG. 7 is a system blockdiagram of the fuel cell system 12 including the hydrogen supplyapparatus according to Embodiment 4. The configuration of the fuel cellsystem 12 according to Embodiment 4 is basically similar to that of thefuel cell system 11 according to Embodiment 3 described above. The fuelcell system 12 according to Embodiment 4 is different from the fuel cellsystem 11 according to Embodiment 3 in that a heater 23 b and athermometer 24 b are provided. It should be noted that the componentsalready described above are identified by the same reference numerals,and thus the detailed description thereof will be omitted.

The thermometer 24 b detects the temperature of the odorant stored inthe odorant tank 5. The detected temperature is inputted to the ECU 4.The heater 23 b is provided at a lower part of the odorant tank 5, andheats the hydrogen gas, stored in the odorant tank 5, by the control ofthe ECU 4. The position at which the heater 23 b is placed may be anyposition as long as the odorant stored in the odorant tank 5 can beheated, and is not limited to the lower part of the odorant tank 5.However, the odorant in a solid form or in a liquid form is accumulatedat the lower part of the odorant tank 5, and therefore, the odorant canbe efficiently heated by placing the heater 23 b at the lower part ofthe odorant tank 5.

Next, the vapor pressure control of the odorant according to Embodiment4 will be described. FIG. 8 is a flow chart illustrating the vaporpressure control of the odorant according to Embodiment 4. First, theECU 4 obtains the temperature of the odorant, stored in the odorant tank5, by the thermometer 24 b (Step 401).

Then, the ECU 4 predicts how the temperature of the hydrogen gas,supplied from the high-pressure hydrogen tank 2, is reduced due toadiabatic expansion (Step 402). The temperature variation in thehydrogen gas due to adiabatic expansion is obtained as data beforehand,and based on this data, how the temperature of the hydrogen gas isreduced due to adiabatic expansion can be predicted. Further, thetemperature of the hydrogen gas supplied from the high-pressure hydrogentank 2 may be measured for a certain period of time, and based on thismeasurement, how the temperature is reduced thereafter may be predicted.

Subsequently, the ECU 4 heats the odorant, stored in the odorant tank 5,by the heater 23 b so that the odorant reaches a necessary vaporpressure (Step 403). The ECU 4 can determine the heater heating amountbased on the temperature of the odorant obtained, the prediction of howthe temperature of the hydrogen gas is reduced, and the property of theodorant.

As described above, by carrying out the control so that the heaterheating amount is determined based on the temperature of the odorant,the temperature of the hydrogen gas, and the property of the odorant,the temperature of the odorant to be added to the hydrogen gas is raisedin advance, and the odorant reaches a necessary vapor pressure, it ispossible to prevent the liquefaction or solidification of the odorant,resulting from the cooling thereof by the hydrogen gas whose temperaturehas been reduced.

Embodiment 5

In addition to the above-described embodiments, for example, thehydrogen gas, to which the odorant has been added, may be heated. FIG. 9is a schematic block diagram showing a fuel cell system 13 including ahydrogen supply apparatus according to Embodiment 5. The configurationof the fuel cell system 13 according to Embodiment 5 is basicallysimilar to that of the fuel cell system 11 according to Embodiment 3.The fuel cell system 13 according to Embodiment 5 is different inconfiguration from the fuel cell system 11 according to Embodiment 3 inthat a heater 23 c and a thermometer 24 c are further provided. The fuelcell system 13 according to Embodiment 3 includes the heater 23 c, thusmaking it possible to heat the hydrogen gas, to which the odorant hasbeen added through the buffer tank 6.

It should be noted that the heating of the hydrogen gas, to which theodorant has been added, may be carried out by obtaining the temperatureof the hydrogen gas to which the odorant has been added, and by heatingthe hydrogen gas, to which the odorant has been added, to the extentthat the odorant will not be liquefied or solidified, in addition to theexecution of the control similar to the temperature control of thehydrogen gas according to Embodiment 3, for example.

Even if the hydrogen gas is heated by the heater 23 a, the temperatureof the hydrogen gas is gradually reduced thereafter in a below-freezingenvironment or the like. However, the fuel cell system 13 according toEmbodiment 5 can heat the hydrogen gas again after the odorant has beenadded to the hydrogen gas, and can prevent the liquefaction orsolidification of the odorant.

Embodiment 6

Further, in the case where the hydrogen gas mixed with the odorant isstored in the high-pressure hydrogen tank 2, the hydrogen gas mixed withthe odorant may be heated outside of the high-pressure hydrogen tank.FIG. 10 is a schematic block diagram showing a fuel cell system 14including a hydrogen supply apparatus according to Embodiment 6. Theconfiguration of the fuel cell system 14 according to Embodiment 6 isbasically similar to that of the fuel cell system 10 according toEmbodiment 1. The fuel cell system 14 according to Embodiment 6 isdifferent in configuration from the fuel cell system 10 according toEmbodiment 1 in that a heater 23 d and a thermometer 24 d are providedinstead of the heater 23 and the thermometer 24 in Embodiment 1,respectively. The fuel cell system 14 according to Embodiment 6 includesthe heater 23 d and the thermometer 24 d, thus making it possible toheat the hydrogen gas mixed with the odorant and supplied from thehigh-pressure hydrogen tank 2. As a result, the odorant can be preventedfrom being liquefied or solidified.

It should be noted that the temperature control of the hydrogen gasmixed with the odorant can be carried out by the ECU 4 based on thetemperature of the hydrogen gas mixed with the odorant, detected by thethermometer 24 d. FIG. 11 is a flow chart illustrating the temperaturecontrol of the hydrogen gas according to Embodiment 6. The ECU 4 obtainsthe temperature of the hydrogen gas, mixed with the odorant, by thethermometer 24 d (Step 501), and determines whether the obtainedtemperature of the hydrogen gas, mixed with the odorant, is equal to orlower than a predetermined temperature T4 (Step 502). Then, if thetemperature of the hydrogen gas, mixed with the odorant, is determinedto be equal to or lower than the predetermined temperature T4, the ECU 4heats the hydrogen gas, mixed with the odorant, by the heater 23 (Step503). On the other hand, if the temperature of the hydrogen gas mixedwith the odorant is not determined to be equal to or lower than thepredetermined temperature T4, the ECU 4 ends the temperature control ofthe hydrogen gas mixed with the odorant. It should be noted that thepredetermined temperature T4 may be the melting point or the boilingpoint of the odorant.

In this manner, since the hydrogen supply apparatus according to thepresent invention is satisfactory so long as the temperature of thehydrogen gas to be supplied can be maintained at a temperature at whichthe hydrogen gas is easily mixed with the odorant, the present inventionis not limited to the foregoing embodiments, and further includes acombination thereof as far as possible.

It should be noted that each of the embodiments has been described usingan example in which a hydrogen gas is used as a fuel gas. However, thepresent invention is not limited thereto, but examples of the fuel gasinclude a natural gas, and an LPG. Therefore, the present invention maybe implemented as a fuel gas supply apparatus.

INDUSTRIAL APPLICABILITY

The fuel gas supply apparatus according to the present invention iscapable of suppressing a temperature reduction in fuel gas even at a lowtemperature, and is useful for the detection of the fuel gas leakagewhen an odorant and a fuel gas are mixed.

Note 1

A hydrogen supply apparatus characterized by including: a gas storageportion which stores a hydrogen gas mixed with an odorant; a gas supplyportion which supplies the hydrogen gas from the gas storage portion; agas temperature detection portion which detects a temperature of thehydrogen gas stored in the gas storage portion; and a gas temperaturereduction suppression portion which suppresses a temperature reductionin hydrogen gas stored in the gas storage portion, when the temperatureof the hydrogen gas detected by the gas temperature detection portion isequal to or lower than a predetermined temperature.

Note 2

A hydrogen supply apparatus according to Note 1, characterized in thatthe predetermined temperature is equal to or higher than a melting pointof the odorant.

Note 3

A hydrogen supply apparatus according to Note 1, characterized in thatthe predetermined temperature is equal to or higher than a boiling pointof the odorant.

Note 4

The hydrogen supply apparatus according to any one of Note 1 to Note 3,characterized by further including a heating portion which increases thetemperature of the hydrogen gas, in which the gas temperature reductionsuppression portion suppresses a temperature reduction in hydrogen gasby the heating portion.

Note 5

The hydrogen supply apparatus according to any one of Note 1 to Note 3,characterized in that the gas temperature reduction suppression portiondecreases an amount of the hydrogen gas supplied by the gas supplyportion, to thereby suppress a temperature reduction in hydrogen gas.

1. A hydrogen supply apparatus, comprising: a gas storage portion whichstores a hydrogen gas; an odorant addition portion which adds an odorantto the hydrogen gas; a temperature adjustment portion which adjusts atemperature of at least one of the hydrogen gas, the odorant, and thehydrogen gas to which the odorant has been added, so as to suppress theodorant mixed with the hydrogen gas from being solidified or liquefied;an odorant temperature detection portion which detects the temperatureof the odorant to be added by the odorant addition portion; and aprediction portion which obtains, as data, a temperature variation inthe hydrogen gas supplied from the gas storage portion, which is causedby adiabatic expansion, and for predicting, based on the data, how thetemperature of the hydrogen gas supplied from the gas storage portion isreduced due to adiabatic expansion, wherein the temperature adjustmentportion has a heating portion which increases the temperature of theodorant added by the odorant addition portion, when the temperature ofthe odorant detected by the odorant temperature detection portion isequal to or lower than a predetermined temperature, and wherein theheating portion applies heat to the odorant, added to the hydrogen gas,in accordance with a heating amount determined based on: the temperatureof the odorant detected by the odorant temperature detection portion,how the temperature of the hydrogen gas is reduced predicted by theprediction portion, and a property of the odorant including at least oneof a boiling point and a melting point of the odorant.
 2. A hydrogensupply apparatus according to claim 1, further comprising a stored gastemperature detection portion which detects the temperature of thehydrogen gas stored in the gas storage portion, wherein the temperatureadjustment portion has a gas temperature reduction suppression portionwhich suppresses a temperature reduction in hydrogen gas stored in thegas storage portion, when the temperature of the hydrogen gas detectedby the stored gas temperature detection portion is equal to or lowerthan a predetermined temperature.
 3. A hydrogen supply apparatusaccording to claim 1, further comprising a hydrogen gas temperaturedetection portion which detects the temperature of the hydrogen gassupplied from the gas storage portion, wherein the temperatureadjustment portion has a heating portion which increases the temperatureof the hydrogen gas supplied from the gas storage portion, when thetemperature of the hydrogen gas detected by the hydrogen gas temperaturedetection portion is equal to or lower than a predetermined temperature.4. (canceled)
 5. A hydrogen supply apparatus according to claim 1,further comprising a hydrogen gas temperature detection portion whichdetects the temperature of the hydrogen gas supplied from the gasstorage portion, wherein the temperature adjustment portion has aheating portion which increases the temperature of the odorant when atleast one of the temperature of the hydrogen gas detected by thehydrogen gas temperature detection portion and the temperature of theodorant detected by the odorant temperature detection portion meets apredetermined condition.
 6. A hydrogen supply apparatus according toclaim 1, further comprising a hydrogen gas temperature detection portionwhich detects the temperature of the hydrogen gas supplied from the gasstorage portion, wherein the temperature adjustment portion has aheating portion which increases the temperature of the hydrogen gaswhich is supplied from the gas storage and to which the odorant has beenadded by the odorant addition portion, when the temperature of thehydrogen gas detected by the hydrogen gas temperature detection portionis equal to or lower than a predetermined temperature.
 7. A hydrogensupply apparatus according to claim 1, further comprising a hydrogen gassupply amount adjustment portion which adjusts a supply amount of thehydrogen gas supplied from the gas storage portion, wherein thetemperature adjustment portion decreases the supply amount of thehydrogen gas, supplied from the gas storage portion, by the hydrogen gassupply amount adjustment portion, to thereby suppress a temperaturereduction in hydrogen gas.
 8. A hydrogen supply apparatus according toclaim 2, wherein the predetermined temperature is equal to or higherthan a melting point of the odorant.
 9. A hydrogen supply apparatusaccording to claim 2, wherein the predetermined temperature is equal toor higher than a boiling point of the odorant.
 10. A hydrogen supplyapparatus, comprising: a gas storage portion which stores a hydrogen gasmixed with an odorant; a gas supply portion which supplies the hydrogengas from the gas storage portion; a gas temperature detection portionwhich detects the temperature of the hydrogen gas stored in the gasstorage portion; a gas temperature reduction suppression portion whichsuppresses a temperature reduction in hydrogen gas stored in the gasstorage portion, when the temperature of the hydrogen gas detected bythe gas temperature detection portion is equal to or lower than apredetermined temperature; an odorant temperature detection portionwhich detects the temperature of the odorant to be mixed with thehydrogen gas; and a prediction portion which obtains, as data, atemperature variation in the hydrogen gas supplied from the gas storageportion, which is caused by adiabatic expansion, and for predicting,based on the data, how the temperature of the hydrogen gas supplied fromthe gas storage portion is reduced due to adiabatic expansion, whereinthe predetermined temperature is set as a temperature at which theodorant to be mixed with the hydrogen gas is solidified or liquefied,wherein the gas temperature reduction suppression portion has a heatingportion which increases the temperature of the odorant added by theodorant addition portion, when the temperature of the odorant detectedby the odorant temperature detection portion is equal to or lower thanthe predetermined temperature, and wherein the heating portion appliesheat to the odorant, added to the hydrogen gas, in accordance with aheating amount determined based on: the temperature of the odorantdetected by the odorant temperature detection portion, how thetemperature of the hydrogen gas is reduced predicted by the predictionportion, and a property of the odorant including at least one of aboiling point and a melting point of the odorant.
 11. A hydrogen supplyapparatus according to claim 10, further comprising a hydrogen gastemperature detection portion which detects the temperature of thehydrogen gas supplied from the gas storage portion, wherein thetemperature adjustment portion has a heating portion which increases thetemperature of the hydrogen gas supplied from the gas storage portion,when the temperature of the hydrogen gas detected by the hydrogen gastemperature detection portion is equal to or lower than a predeterminedtemperature.
 12. A hydrogen supply apparatus according to claim 10,further comprising a hydrogen gas supply amount adjustment portion whichadjusts a supply amount of the hydrogen gas supplied from the gasstorage portion, wherein the temperature adjustment portion decreasesthe supply amount of the hydrogen gas, supplied from the gas storageportion, by the hydrogen gas supply amount adjustment portion, tothereby suppress a temperature reduction in hydrogen gas.
 13. A hydrogensupply apparatus according to claim 11, wherein the predeterminedtemperature is equal to or higher than a melting point of the odorant.14. A hydrogen supply apparatus according to claim 11, wherein thepredetermined temperature is equal to or higher than a boiling point ofthe odorant.
 15. A fuel gas supply apparatus, comprising: a gas storageportion which stores a fuel gas; an odorant addition portion which addsan odorant to the fuel gas; a temperature adjustment portion whichadjusts the temperature of at least one of the hydrogen gas, theodorant, and the hydrogen gas to which the odorant has been added, so asto suppress the odorant mixed with the fuel gas from being solidified orliquefied; an odorant temperature detection portion which detects thetemperature of the odorant to be added by the odorant addition portion;and a prediction portion which obtains, as data, a temperature variationin the fuel gas supplied from the gas storage portion, which is causedby adiabatic expansion, and for predicting, based on the data, how thetemperature of the fuel gas supplied from the gas storage portion isreduced due to adiabatic expansion, wherein the temperature adjustmentportion has a heating portion which increases the temperature of theodorant added by the odorant addition portion, when the temperature ofthe odorant detected by the odorant temperature detection portion isequal to or lower than a predetermined temperature, and wherein theheating portion applies heat to the odorant, added to the fuel gas, inaccordance with a heating amount determined based on: the temperature ofthe odorant detected by the odorant temperature detection portion, howthe temperature of the fuel gas is reduced predicted by the predictionportion, and a property of the odorant including at least one of aboiling point and a melting point of the odorant.
 16. A fuel gas supplyapparatus according to claim 15, further comprising a stored gastemperature detection portion which detects the temperature of the fuelgas stored in the gas storage portion, wherein the temperatureadjustment portion has a gas temperature reduction suppression portionwhich suppresses a temperature reduction in fuel gas stored in the gasstorage portion, when the temperature of the fuel gas detected by thestored gas temperature detection portion is equal to or lower than apredetermined temperature.
 17. A fuel gas supply apparatus according toclaim 15, further comprising a fuel gas temperature detection portionwhich detects the temperature of the fuel gas supplied from the gasstorage portion, wherein the temperature adjustment portion has aheating portion which increases the temperature of the fuel gas suppliedfrom the gas storage portion, when the temperature of the fuel gasdetected by the fuel gas temperature detection portion is equal to orlower than a predetermined temperature.
 18. (canceled)
 19. A fuel gassupply apparatus according to claim 15, further comprising a fuel gastemperature detection portion which detects the temperature of the fuelgas supplied from the gas storage portion, wherein the temperatureadjustment portion has a heating portion which increases the temperatureof the odorant when at least one of the temperature of the hydrogen fuelgas detected by the fuel gas temperature detection portion and thetemperature of the odorant detected by the odorant temperature detectionportion meets a predetermined condition.
 20. A fuel gas supply apparatusaccording to claim 15, further comprising a fuel gas temperaturedetection r portion which detects the temperature of the fuel gassupplied from the gas storage portion, wherein the temperatureadjustment has a heating portion which increases the temperature of thefuel gas which is supplied from the gas storage portion and to which theodorant has been added by the odorant addition portion, when thetemperature of the fuel gas detected by the fuel gas temperaturedetection portion is equal to or lower than a predetermined temperature.21. A fuel gas supply apparatus according to claim 15, furthercomprising a fuel gas supply amount adjustment portion which adjusts asupply amount of the fuel gas supplied from the gas storage portion,wherein the temperature adjustment portion decreases the supply amountof the fuel gas, supplied from the gas storage portion, by the fuel gassupply amount adjustment portion, to thereby suppress a temperaturereduction in fuel gas.
 22. A fuel gas supply apparatus according toclaim 16, wherein the predetermined temperature is equal to or higherthan a melting point of the odorant.
 23. A fuel gas supply apparatusaccording to claim 16, wherein the predetermined temperature is equal toor higher than a boiling point of the odorant.
 24. A fuel gas supplyapparatus, comprising: a gas storage portion which stores a fuel gasmixed with an odorant; a gas supply portion which supplies the fuel gasfrom the gas storage portion; a gas temperature detection portion whichdetects the temperature of the fuel gas stored in the gas storageportion; and a gas temperature reduction suppression portion whichsuppresses a temperature reduction in fuel gas stored in the gas storageportion, when the temperature of the fuel gas detected by the gastemperature detection portion is equal to or lower than a predeterminedtemperature, wherein the predetermined temperature is set as atemperature at which the odorant to be mixed with the fuel gas issolidified or liquefied.
 25. A fuel gas supply apparatus according toclaim 24, further comprising a fuel gas temperature detection portionwhich detects the temperature of the fuel gas supplied from the gasstorage, wherein the temperature adjustment portion has a heatingportion which increases the temperature of the fuel gas supplied fromthe gas storage portion, when the temperature of the fuel gas detectedby the fuel gas temperature detection portion is equal to or lower thana predetermined temperature.
 26. A fuel gas supply apparatus accordingto claim 24, further comprising a fuel gas supply amount adjustmentportion which adjusts a supply amount of the fuel gas supplied from thegas storage portion, wherein the temperature adjustment portiondecreases the supply amount of the fuel gas, supplied from the gasstorage portion, by the fuel gas supply amount adjustment portion, tothereby suppress a temperature reduction in hydrogen gas.
 27. A fuel gassupply apparatus according to claim 24, wherein the predeterminedtemperature is equal to or higher than a melting point of the odorant.28. A fuel gas supply apparatus according to claim 24, wherein thepredetermined temperature is equal to or higher than a boiling point ofthe odorant.
 29. A hydrogen supply apparatus according to claim 1,wherein: the gas storage portion comprises a plurality of gas storageportions; the apparatus further comprises a stored gas temperaturedetection portion which detects the temperature of the hydrogen gasstored in the gas storage portion; and when the temperature of thehydrogen gas detected by the stored gas temperature detection portion isequal to or lower than a predetermined temperature, the temperatureadjustment portion selects, out of the plurality of gas storageportions, the gas storage portion the temperature of which is higherthan the predetermined temperature, to thereby supply the hydrogen gasinside the gas storage portion to a fuel cell.
 30. A hydrogen supplyapparatus according to claim 2, wherein the gas temperature reductionsuppression portion is a heating portion which heats the hydrogen gasstored in the gas storage portion, and wherein the heating portion isdisposed at a lower part of the gas storage portion.
 31. A fuel gassupply apparatus according to claim 15, wherein the gas storage portioncomprises a plurality of gas storage portions; the apparatus furthercomprises a stored gas temperature detection portion which detects thetemperature of the fuel gas stored in the gas storage portion; and whenthe temperature of the fuel gas detected by the stored gas temperaturedetection portion is equal to or lower than a predetermined temperature,the temperature adjustment portion selects, out of the plurality of gasstorage portions, the gas storage portion the temperature of which ishigher than the predetermined temperature, to thereby supply the fuelgas inside the gas storage portion to a fuel cell.
 32. A fuel gas supplyapparatus according to claim 16, wherein the gas temperature reductionsuppression portion is a heating portion which heats the fuel gas storedin the gas storage portion, and wherein the heating portion is disposedat a lower part of the gas storage portion.